I have to start by saying that when they do work, the Prismacolor Premier pencils are a joy to use. However they are far to soft resulting in you having to sharpening them with annoying regularity.
The other issue is the tendency for the leads to break. The only conclusion that I’ve been able to come up with is that because of the poor build quality of the Prisma’s, with emphasis on some of the pencil leads being off centre, leads breaking must be the result.
Prismacolor Problems: Leads are off center/centre
As for the build quality, when I looked at the Black and White in the set, the wood looks to be totally different. Not sure what is going on with the Prismacolor brand, but the comments are that since Prisma moved their production to South America, quality and customer service (which appears to be none existent) has suffered.